i9o8] YAMANOUCHI—SPOROGEXESIS IN NEPURODIVM ^ 



aOTees with the views maintained 



( 



Cardiff's (12) studies of synapsis and reduction ia several forms 

 of flowering plants and in Botrychhim obUquum paid particular atten- 

 tion to the formation of the spirem and its behavior up to the forma- 

 tion of bivalent chromosomes in the heterotypic mitosis. According 

 to him, paired threads, which appear in the presynaptic stage of the 

 nucleus, fuse during synapsis and again spHt longitudinally after 

 s}Tiapsis, probably along the line of the previous fusion. 



In 1007 a paper entitled *' Studies in aposporv and anoramv in 



fern 



minary notes were published in 1003 and 



This paper deals directly with the matter indicated by the title, but 

 some stages in the division of the spore mother cell are described in 

 three forms of Lastrea and one species of Scolopendrium. The paper 

 is accompanied by many important figures, but only three of the 

 spore mother cells with heterotypic chromosomes are given, so far 



T 



as sporogenesis is concerned. 



Recently there appeared two papers, one by Burlixgame (10) 

 on Ophioglossales, and the other by Gregoire (24), with the title 

 *^La formation des gemini heteroivpiques dans les vegetaux." Buit- 



■ 



ltxgame's paper is chiefly devoted to a study of the sporangium. 

 From the cytological standpoint Gregoire's paper is verj- important. 

 His views, which were published in 1904 (25), concerning the structure 

 of the resting nucleus of the spore mother cell, interpretation of s\7iap- 

 sis, formation of chromosomes of the heterotypic mitosis, and distri- 

 bution of the daughter chromosomes in the first and second divisions, 



based chieflvuDon Bergh's studies 



and 



OIRE 



results of hfe own examination of Osmunda regalis and four mono- 



confirra 



Nephrodiuni 



^ly present investigation of NepJirodium molle Desv. was carried 

 on in order to imderstand the characteristics of the nuclear beha\nor 

 of this species, and to obtain the knowledge prerequisite for a study 

 of apogamy in the same spzcies. Consequently this paper should 



rf 



